Design and analysis of nonequilibrium separation processes

Influence of mass transfer in distillation: Residue curves and total reflux

“…Sridhar et al 5 begin their analysis of simple batch evaporation in much the same way, as do all others, with the differential material balance for the liquid phase (expressed here in a form slightly different from, but formally equivalent to, that in Sridhar et al 5 )…”

“…This is the relationship used by Sridhar et al 5 and implies that the molar fluxes have mixed signs (given that the heats of vaporization have the same sign). That is, some components would evaporate, whereas others would be condensing.…”

“…Toward this end there have been a few recent attempts to develop a framework for the construction of RCMs that explicitly include mass transfer rate equations in the model, [4][5][6] Such attempts are, as shown in the Appendix, seriously flawed; mass transfer rate equations have no place in a model for the residue curve map as it is described by Doherty and Malone. 1…”

Heterogeneous Nonequilibrium Mole Fraction Curve Maps

“…In a recent article, a strategy was developed to draw mole fraction curve maps for homogeneous mixtures, using the nonequilibrium model that involves the utilization of mass-transfer models. However, it must be emphasized that these curves were incorrectly referred to as “residue curves”.…”

Effects of vapor–liquid mass transfer on feasibility of reactive distillation

“…Thiel et al (1997a, 1995b) also used residue curve maps for fuel ether systems before formulating a rigorous mass‐transfer model, although the residue curves were still calculated assuming phase equilibrium. Nonequilibrium residue curve maps were recently addressed by Sridhar et al (2002). A comprehensive review of mass‐transfer models used in reactive distillation was published by Taylor and Krishna (2000).…”